Connective Tissues

Most diverse & abundant tissue

Main Role

Strength against forcesProtect organsMaintain organ shapeProvide frame for muscle pull

2 ComponentsCells + matrix

Cells Matrix ~ ground substance

Fibers + “Protein Glue” + WaterNon-living

Origin of ConnectiveTissue

Just notice that the cells, thus tissue, thus system originates from the mesoderm, as you learned previously

Connective Tissue Cells

FibrocyteChondrocyteOsteocyteHematopoietic stem cell (in bone

marrow) red blood cell makers

Types of Fibers

Reticular keeps cells in place

Collagen resists stretch

Elastic allows stretch

Tissues Described By :

Amount of fibers : # of cells Arrangement of fibers in matrixType(s) of fiber in matrixAbility, function or location

Types

Connective properCartilageBlood Bone

Connective Tissue Proper (1/4)

Loose few fibers : more cells

Loose & AdiposeFiber type: almost noneFunction: Energy storage, protection

LocationUnder skin Around organs Behind eyeballsFastens kidneys

Loose & Reticular

Fibers: reticular Function: scaffold for cell migration

Location: lymph organs Lymph nodes bone marrow spleen

Loose & Areolar

Fiber Type: collagen, reticular, elasticFunction: retains water; connects

epithelium to …?

Location Under epitheliaAround organsSurround capillaries

Densemore fibers : few cells

 

Connective Tissue Proper (1/4)

Dense & Regular Description

Parallel directioncollagen & some elastic fibersHigh stretch strengthPoor vascular supply

Functionstress in one direction

LocationTendons & ligamentsBundle ends of muscles

Dense & Irregular Description

Multi directioncollagen & elastic fibers Resist stretch

Function Withstand tensionstructural strength

LocationDermis of skindigestive tractjoints and organs

Dense & Elastic Description

Elastic fibers, very little collagenHigh elasticity

Function Allow stretch

LocationAlveoli of lungsArteries

*Cartilage (1/4)

3 types Description

Avascular, no nervesMatrix up to 80% water

A. Hyaline (Glassy)

Description a few collagen fibers

FunctionResist repetitive stress Support & reinforcecushion

LocationEnd of long bonesCostal cartilage of ribsnose, trachea, & larynx

B. Elastic Description

More elastic fibersA Few collagen

Function Maintain shapeGreat flexibility

Locationexternal earEpiglottis

C. Fibrous Description

Thick collagen fibers

FunctionTensile strengthAbsorb compression

LocationIntervertebral discsPubis symphysisDisc of knee joint

*Blood Tissue (1/1)

DescriptionCells + fluid matrix + dissolved fibers

Functiontransport gases, nutrients, & waste

Locationblood vessels